For \(\Xi \)  parametrization, the full redshift dependence of the GW friction is described by two parameters \((\Xi _0, n)\) , with which the ratio between the GW and electromagnetic luminosity distances can be written as [1]}
\(\frac{d_L^{\rm gw}(z)}{d_L^{\rm em} (z)} \equiv \Xi (z) = \Xi _0 + \frac{1-\Xi _0}{(1+z)^n}.\) 
